Sewing machine



Aug. 7, 1956 KISAKU FUJITA SEWING MACHINE 3 Sheets-Sheet l NN QN FiledSept. 24. 1952 INVENTOR 54/121 flg/ #0 BY W-Zi ATTORNEY.

7, 1956 KlSAKU FUJZTA SEWING MACHINE 3 Sheets-Sheet 2 Filed Sept. 24,1952 INVENTOR.

Wow/f //0 BY A TTORNEY;

A g- 7, 1956 KISAKU FUJITA SEW ING MACHINE 3 Sheets-Sheet 3 Filed Sept.24, 1952 I N VEN TOR.

A TTORNE Y.

United States Patent SEWING MACHINE Kisaku Fujita, Hamamatsu-shi,Shizuoka-ken, Japan Application September 24, 1952, Serial No. 311,238Claims priority, application Japan October 6, 1951 9 Claims. (Cl.112-158) The present invention relates to a sewing machine, having animproved control device for changing from straight to zigzag stitchesand vice versa.

Hitherto, in the usual sewing machine the control device for changingthe straight and zigzag stitch is very complex and the zigzag widthcontrol dial is usually arranged at a position differing from theposition of the stitch position control dial. Therefore, the relativeadjustment of the two control dials is very troublesome and the handlingof the dials is very inconvenient.

The object of this invention is to provide a relatively simple controldevice capable of changing easily the sewing operation from straightstitch to zig-zag stitch or vice versa and of adjusting simply andindependently each of the said stitchings.

According to this invention, in. order to attain the said object, thezig-zag width control dial and stitch position control dial are arrangedconcentrically in the same position so that each of them may be adjustedindividually and independently of each other.

Furthermore, according to this invention. each of the dials is providedwith a suitable graduation so that the positions of the adjustments andthe relative position of the adjustments may be easily understood. Thecontrol device is also constructed so that any manual operation of thecontrol dials may be very smooth and moreover each of the dials may belocked surely and automatically to its adjusted position during theirnonoperation.

Hitherto, in the usual control device such as above mentioned there isthe disadvantage that a reeling stitch i. e. a nonrectilinear straightstitch may occur owing to the effect exerted on the needle by any rattleor vibration caused by wear of the zig-zag stitching mechanism.

With the object of preventing this disadvantage, hitherto, variousconstructions have been contrived. It is diflicult, however, to preventeffectively the reeling stitch.

Therefore, the further object of this invention is to improve the seWingmachine provided with concentric dials such-as above mentioned so thatsaid reeling stitch may be effectively prevented. This object hasbeenattained, according to this invention, by a special locking devicearranged at the operating rod of the zig-zag stitching mechanism, thisdevice being hereinafter more particularly described in connection withthe accompanying drawings. According to such construction, the vibrationoccurring in any part of the zigzag stitching mechanism will not betransmitted towards the sewingneedle beyond the operating rod.Therefore, the operation of the needle will become very stable,resulting in eifectiveprevention of the reeling stitch.

The said object, other objects, and advantages of this invention willbecome more readily apparent from the following explanation inconnection with the embodiment shown in the accompanying drawings. Thisembodiment is a preferred form of this invention.

Fig. l is a side elevation partially in section.

Fig. 2 is a sectioned plan view taken along the line xx in Fig. 1.

Fig. 3 is a perspective view of the main operating structure.

Fig. 4 is a sectional elevation taken along the line yy in Fig. 2.

Fig. 5 is an internal side view as seen along the line xx in Fig. 2.

Fig. 6 is a sectional elevation of the control dials taken along theline zz in Fig. 5.

In Figs. 1, 2, 3, and 4, 2 is a sewing bar supported swingably by boss3, 1 is a needle holder supported in the bar 2 so that it may be slidupwardly and downwardly, 4 is a driving shaft for driving the needleholder 1 through a crank 5, link 6, and supporter 7. 8 is a screw pinfixing the base part of the supporter 7 with the needle holder 1. 9 isan operating rod for zigzag stitching, one end 10 of the said rod beingpivoted at a pivot 11. At the base part of the operating rod 9 is fixeda forked body 12 to be used for transmitting the zigzag stitch controland stitch position control towards the needle bar. The joint piece 13which is provided at the base end of the forked body 12 is fitted in theslot 15 of the controlling frame 14 so that any zigzag swing may betransmitted towards the swing bar 2 through the forward and backwardmotion of the operating rod 9, the said motion being caused by the swingof the controlling frame 14 around the swing shaft 16. The amplitude ofthe swing can be adjusted in accordance with the position of the jointpiece 13 along the slot 15. When the position of the joint piece in theslot 15 coincides with the center position of the swing shaft 16, theoperating rod 9 does not swing in spite of swing of the controllingframe 14. However, in proportion to the increment of the distancebetween the swing shaft 16 and the joint piece 13, the'swing amplitudeof the operating rod becomes larger and larger. As is clear from Fig. 4,the swing shaft 16 of the controlling frame 14 is supported rotatably onthe U type frame or yoke 17 and the legs 17' and 17" of the frame 17 aresupported rotatably on the shaft 18. Therefore, the shaft 16 receives aswing caused by the rotation of the triangular cam 20 fitted in theforked arms 19 of the shaft 16 and causes the swing of the controllingframe 14. The triangular cam 20 is fixed on the shaft 18 driven by theprime driving shaft 4 through the gears 21 and 22, the shaft 18 beingsupported by the boss 23. 72 is a stitch graduated plate, 73 is a feedregulating lever, and 74 is a feed regulating screw knob.

As is clear from the above description, for adjustment of the amplitudeof the zigzag stitch, it is only necessary to alter the relativeposition between the joint piece 13 and the slot 15 in the controllingframe 14. On the other hand, for adjustment of the stitch position ofthe needle bar it is only necessary to adjust forwards and backwards theposition of the swing shaft 16 of the controlling frame 14. The forkedpart 24 of the forked body 12 and the forked part 26 of the forked body25 fixed on an end of the U type frame 17 are arranged so as toaccomplish these adjustments. The forked parts 24 and 26 define camfollower surfaces between their arms or tines and receive cam rollers 29and 30 to bear against these cam follower surfaces, the cam rollers 29and 30 being supported by the controlling levers 27 and 28. When theforked part 24 is adjusted upwards or downwards by rotation of the lever27, then the swing amplitude will be adjusted effectively and when theposition of the shaft 16 in the U type frame 17 is displaced leftwardsor rightwards through the forked body 25 by means of rotation of thelever 28, then the adjustment of the stitch position will be doneeifectively.

As is shown in Figs. 2, 4, and 6, the lever 27 is connected with the endof the shaft 32 of the control dial 31 and the lever 28 is connectedwith the end of the tubular shaft 43 of the control dial 33. 34 is astopper pin, 35

is a pin hole, 36 is a lock nut, 37 is a nut for fixing the lever 28with the shaft 43. The shaft 32 and the shaft 43 are supported,respectively, at the inside and outside of the supporting tubular shaft38 so that each of them may be rotated independently of each other.Moreover, the shaft 32 is supported elastically by means of a spring 39so that it may be shifted in the axial direction. 40 is a springpressing the lever 28 and the shaft 43 so as to give resistance to therotation of the said parts 28 and 43. 41 is a ring determining therelative position of the parts 43 and 38. 42 is an outer stationaryshaft supporting the shaft 38. The shaft 43 may be directly supported onthe shaft 38 or on the outer shaft 42 fixed on the side wall 49. Theshaft 38 is provided with a sidewardly projecting flange 38 attached tothe outer stationary shaft 42 by means of set screws 48 and 48'. To thelevers 27 and 28 are fixed the pins 46 and 47 through the spring washers44 and 45. 50 and 51 are locking parts facing the pins 46 and 47. As isclear from Fig. 5, the part 50 is an arcuate zigzag slot having aserrated surface formed in the piece 38 fixed on the flange 38' and thepart 51 is formed as the zigzag serrated end of an elastic wire 52, thebase end of the wire being supported on the side wall 49 by a stopperplate 53.

The dials 31 and 33 may be operated very effectively as follows. If thedial 31 is pushed against the spring 39, the stopper pin 46 will bedisconnected from the locking slot 50, resulting in smooth andindependent operation of the dial 31. If the dial 31 is released after asuitable adjustment, the dial 31 will be automatically pushed outwardsby the spring 39 and the stopper pin 46 will be caught securely at asuitable position in the slot 50. On the other hand, if the dial 33 isrotated, the pin 47 will be displaced along the zigzag wire end 51receiving a proper pressure of the elastic wire 52, resulting in simpleoperation of the dial.

In a control device such as above described, there is a possibility thatafter operation for a long period, a vibration or rattle may occur owingto wear of the mechanism.

According to this invention, the occurrence of such a rattle has beeneliminated by a special locking device hereinafter particularlydescribed in connection with Fig. 2.

In Fig. 2, 54 is a boss formed on the base part of the machine body A,55 is a boss formed on the side wall 56 at the portion of wall 56opposite boss 54. The shaft 58 of the clipper 57 to be used for pressingthe operating rod 9 is screwed in the boss 54 and in the head of theclipper 57 there is provided a slot 59 for receiving a screw driver tobe used for adjustment of the clipper position. 61 is a rod screwed inthe bushing 60 which is supported in the boss 55, the head of the rod 61being pressed against the operating rod 9 so as to clip the operatingrod 9 between the rod 61 and the clipper 57. 63 is a locking knobsecured to the rod 61 by a screw pin 64.

In Fig. 1, each of the parts 65 and 66 is a pointer attached,respectively, to each of the dials 31 and 33 and made of transparentsynthetic resin so that the pointer position may be clearly seen even ifone of the two pointers lies over the other. 65 and 66 are pointingmarks and 67 and 68 are graduations corresponding to the marks 65 and66. 69 is a mark which is provided on the locking knob 63 so that thefree position or clipping position of the operating rod 9 may be easilyindicated by the mark 70 or 71.

The operation of the control device such as above mentioned is asfollows:

A. In making a straight stitch-When the zigzag width control dial 31 ispushed and rotated until the mark 65 coincides with the zero point ofthe graduation 67, then the operating rod 9 will take the lower positionand the center of the joint piece 13 coincides with the center axis ofthe swing shaft 16 of the controlling frame 14, resulting in cessationof the swing transmission from the controlling frame 14 to the operatingrod 9. In this case the control center of the stitch position coincideswith the zero point. However, the control position of the stitchposition, if necessary, may be adjusted towards the right side or theleft side. If the dial 31 is released after this operation, this dialwill be locked automatically by the engagement of the stopper pin 46with the slot 50.

Next, it the locking knob 63 is rotated so that the mark 69 willcoincide with the locking mark 71, the end 62 of the rod 61 presses theoperating rod 9 towards the clipper 57, resulting in locking of the rod9.

If the driving shaft 4 is operated in the above condition, the straightstitch will be made surely and effectively without receiving any adverseeffect caused by rattle of the mechanism because of the securemaintenance of the operating rod 9 in its locked condition.

B. In making a zigzag stitch.(a) Zigzag stitch along the center line: Inthe condition of the above case A, if the mark 69 is controlled to theposition indicated by the free mark 70 by rotation of the locking knob63, then the rod 61 will be released and the operating rod 9 becomesfree.

Next, if the amplitude controlling dial 31 is rotated so that the jointpiece 13 at the base part of the operating rod 9 departs from theposition of the swing shaft 16 of the controlling frame 14, the swing ofthe said frame 14 will be transmitted to the operating rod 9 and fromthis rod to the swing bar 2, resulting in a zigzag stitch. The amplitudeof the stitching may be adjusted suitably by the graduation 67. If thedial 31 is released, the said mechanism will be locked surely by theengagement of the stopper pin 46 with the locking slot 50.

(b) Zigzag stitch along the line displaced from the center line: Whenthe zigzag course is to be displaced towards the right or left side,position control should be effected in addition to the adjustmentdescribed in the case (a). For the sake of such position control, it isonly necessary to rotate suitably the position controlling dial 33. Thatis, if the dial 33 is rotated towards the right side or the left side,then the U type frame 17 will be rotated around the shaft 18 through thelever 28 and forked body 26, resulting in displacement of the swingshaft 16 towards the left or the right side. As a result, the operatingrod 9 is displaced towards the front or rear side and the swing bar 2 isdisplaced towards the left or the right side. Therefore, the stitchingposition of the needle bar varies. During such control, the mostsuitable position of displacement may be easily decided by the relativeposition of the graduation 68 and the pointing piece 66.

The above description concerns only one illustrative embodiment of thisinvention. As many widely ditferent embodiments of this invention may bemade without departing from the spirit and scope thereof, it is to beunderstood that I do not limit my invention to specific embodimentsthereof except as defined in the appended claims.

I claim:

1. A sewing machine adapted for use selectively for normal straightstitching and for zig-zag sitching comprising, in combination, a machinebody, a bar pivotallymounted at one end in said body for lateralreciprocating movement, a needle carrier mounted in said bar forvertical reciprocating movement, means for vertically reciprocating saidneedle carrier, a connecting rod pivotally connected to said bar forreciprocating said bar horizontally, and means for transmittingreciprocating movements to said connecting rod, said last-named meansbeing adjustable with respect to the amplitude of the reciprocation andbeing adjustable to a neutral point of nonreciprocation for straightstitching, and a locking device for rigidly holding the connecting rodwhen said lastnamed means is in its neutral position, said lockingdevice comprising means defining an adjustable rigid clamping surfacelying on one side of said rod, and means defining a second clampingsurface on the opposite side of said rod, said last-named clampingsurface being movable toward said first-named clamping'surface' to'bringsaid clamping surfaces into frictional engagement with the rod.

2. A sewing machine adapted for use selectively for normal straightstitching and for zig-zag stitching comprising, in combination, amachine body, a bar pivotallymounted at one end in said body for lateralreciprocating movement, a needle carrier mounted in said bar forvertical reciprocating movement, means for vertically reciproeating saidneedle carrier, a connecting rod pivotally connected to said bar forreciprocating said bar horizontally, and means for transmittingreciprocating movements to said connecting rod, said last-named means being adjustable with respect to the amplitude of the reciprocation andbeing adjustable to a neutral point of nonreciprocation for straightstitching, and a locking device for rigidly holding the connecting rodwhen said lastnamed means is in its neutral position, said lockingdevice including a clipper element screwed adjustably on a shaftsupported on the machine body, a locking rod screwed in the machine bodywith its forward end at a position opposite said clipper element withthe connecting rod lying therebetween and a locking knob secured to saidlocking rod for moving the locking rod toward said clipper element.

3. A sewing machine adapted for use selectively for normal straightstitching and for zig-zag stitching comprising, in combination, amachine body, a bar pivotallymounted at one end in said body for lateralreciprocating movement, a needle carrier mounted in said bar forvertical reciprocating movement, means for vertically reciprocating saidneedle carrier, a connecting rod pivotally connected to said bar forreciprocating said bar horizontally, and means for transmittingreciprocating movements to said connecting rod, said last-named meansincluding a pivotally mounted yoke, driven cam means oscillating saidyoke through a predetermined arc during operation of the machine aboutan adjustable axis, means movable with said yoke defining a slot in theplane of the yoke, said slot having the end of said connecting rodadjustably engaged therewith from a point coinciding with said axis to apoint of maximum reciprocation of the connecting rod, means for settingthe position of said connecting rod relatively to said slot, saidlast-named means comprising means connected to said connecting roddefining a cam follower surface, a cam engaged with said surface, meansfor rotating said cam through a predetermined are, said rotating meanscomprising a knob and an arm carrying the cam and means connecting saidknob with said arm, a pin carried by said arm and means defining aserrated surface engaged by said pin, each recess in said serratedsurface thereby defining a step in the movement of the cam through itspredetermined arc, and means for adjusting the relative position of theyoke, said last-named means comprising means connected to said yokedefining a cam follower surface, a cam engaged with said surface, meansfor rotating said cam through a predetermined arc, said rotating meanscomprising a knob and an arm carrying the cam, and means connecting saidknob with said arm, a pin carried by said arm and means defining aserrated surface engaged by said pin, each recess in said serratedsurface thereby defining a step in the movement of the cam through itspredetermined are.

4. A sewing machine adapted for use selectively for normal straightstitching and for zig-zag stitching comprising, in combination, amachine body, a bar pivotallymounted at one end in said body for lateralreciprocating movement, a needle carrier mounted in said bar forvertical reciprocating movement, means for vertically reciprocating saidneedle holder, a connecting rod pivotally connected to said bar forreciprocating said bar horizontally, and means for transmittingreciprocating move ments to said connecting rod, said last-named meansincluding a pivotally mounted yoke, driven cams means oscillating saidyoke through a predetermined arc during operation of the machine aboutan adjustable axis, means movable with said yoke defining a slot in theplane of the yoke, said slot having the end of said connecting rodadjustably engaged therewith from a point coinciding With said axis to apoint of maximum reciprocation of the connecting rod, means for settingthe position of said connecting rod relatively to said slot, saidlast-named means comprising means connected to said connecting roddefining a cam follower surface, a cam engaged with said surface, meansfor rotating said cam through a predetermined arc, said rotating meanscomprising a knob and an arm carrying the cam and means connecting saidknob with said arm, a pin carried by said arm and a plate having a slotwith a serrated side surface engaged by said pin, each recess in saidserrated surface thereby defining a step in the movement of the camthrough its predetermined arc, and means for adjusting the relativeposition of the yoke, said last-named means comprising means connectedto said yoke defining a cam follower surface, a cam engaged with saidsurface, means for rotating said cam through a predetermined arc, saidrotating means comprising a resiliently pressed knob and an arm carryingthe cam, and means connecting said knob with said arm, a pin carried bysaid arm and a resilient wire having an end provided with a serratedsurface engaged by said pin, each recess in said serrated surfacethereby defining a step in the movement of the cam through itspredetermined arc.

5. A sewing machine as defined in claim 3, wherein said knobs areconcentrically arranged.

6. A sewing machine as defined in claim 3, wherein a control dial isprovided for the means for setting the position of the connecting rodrelatively to the slot in the means movable with the yoke and a controldial is pro vided for the means for adjusting the angular position ofthe yoke, said control dial having indicia indicating selected positionsand having cooperating pointers.

7. A sewing machine as defined in claim 3, wherein a control dial isprovided for the means for setting the position of the connecting rodrelatively to the slot in the means movable with the yoke and a controldial is provided for the means for adjusting the angular position of theyoke, said control dial having indicia indicating selected positions andhaving cooperating transparent pointers.

8. A sewing machine adapted for use selectively for normal straightstitching and for zig-zag stitching comprising, in combination, amachine body, a bar pivotally mounted at one end in said body forlateral reciprocable movement, a needle holder mounted in said bar forvertical reciprocable movement, means for vertically reciproeating saidneedle holder, a connecting rod pivotally connected to said bar forreciprocating said bar horizontally, means pivotable about an axis fortransmitting reciprocating movements to said connecting rod, meansmovable with said last-named means and defining a slot, said slot havingthe end of said connecting rod adjustably engaged therein from a pointcoinciding with said axis to a point of maximum reciprocation of theconnecting rod, means for setting the position of said connecting rodrelatively to said slot, and means for adjusting the angular position ofsaid pivotable means, said setting means including a U-shaped memberhaving a first roller carried by a first arm movable therein, saidadjusting means comprising a U-shaped member having a Second rollercarried by a second arm movable therein, one of said arms beingconnected to a shaft and the other of said arms being connected to aconcentric tubular member enclosing said shaft, and control dialsconnected respectively to said shaft and to said tubular member, asecond tubular member connected to the machine body interposed betweensaid shaft and said first-named tubular member, said shaft beingrotatable interiorly of said second tubular member and said first-namedtubular member being rotatable about the interior of said second tubularmember, whereby said shaft and said first-named References Cited in thefile of this patent tubular member may be separately rotated forselectively UNITED STATES PATENTS moving said setting means and said adustmg means.

9. A sewing machine as defined in claim 8, wherein 2914916 T1651 P 1711935 each arm carries a pin and said machine further com- 5 2,202,515Bolt" ct y 28, 1940 prises means defining a serrated surface engaged bythe 2,297,197 B lter Sept. 29, 1942 pin of one of said arms and meansdefining a second FOREIGN PATENTS serrated surface engaged by the pin ofthe other of said arms, and spring means normally urging said pins and444,104 Italy 1949 10 732,819 Germany Mar. 12, 1943 their respectiveserrated surfaces into engagement.

